demand

https://github.com/ConvincibleMedia/ruby-gem-demand

Return a variable if it's present (and optionally of the right type), otherwise a default or nil. Adds a top level demand() method, which replaces long lines of repetitive code to check for nil?/present?/empty?, etc., hard-to-read ternary operators (?:) and if statements. A block can also be specified, which only runs (with the variable) if the checks pass.